diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 513a5dd35..ebd18d76d 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -163,19 +163,37 @@ function maybe_unserialize($original) {
 }
 
 function is_serialized($data) {
-	if ( !is_string($data) ) // if it isn't a string, it isn't serialized
+	// if it isn't a string, it isn't serialized
+	if ( !is_string($data) )
 		return false;
 	$data = trim($data);
-	if ( preg_match("/^[adobis]:[0-9]+:.*[;}]/si",$data) ) // this should fetch all legitimately serialized data
+	if ( 'N;' == $data )
 		return true;
+	if ( !preg_match('/^([adObis]):/', $data, $badions) )
+		return false;
+	switch ( $badions[1] ) :
+	case 'a' :
+	case 'O' :
+	case 's' :
+		if ( preg_match("/^{$badions[1]}:[0-9]+:.*[;}]\$/s", $data) )
+			return true;
+		break;
+	case 'b' :
+	case 'i' :
+	case 'd' :
+		if ( preg_match("/^{$badions[1]}:[0-9.E-]+;\$/", $data) )
+			return true;
+		break;
+	endswitch;
 	return false;
 }
 
 function is_serialized_string($data) {
-	if ( !is_string($data) ) // if it isn't a string, it isn't a serialized string
+	// if it isn't a string, it isn't a serialized string
+	if ( !is_string($data) )
 		return false;
 	$data = trim($data);
-	if ( preg_match("/^s:[0-9]+:.*[;}]/si",$data) ) // this should fetch all serialized strings
+	if ( preg_match('/^s:[0-9]+:.*;$/s',$data) ) // this should fetch all serialized strings
 		return true;
 	return false;
 }
@@ -1202,5 +1220,4 @@ function _mce_add_direction_buttons($input) {
 
 	return $input;
 }
-
 ?>